Deferred task from QDOCS-460 - Fix callouts in code-snippets on PV2:

From QDOCS-460...

PV2 provides limited support for unicode icons, so when we add the unicode for upstream icons and use the icon: image mode, other icons in PV2 break. PV2 needs a png of that icon somewhere.
Icons for admonitions and callouts are hardcoded in PV2 and need 'font' mode on to work. But we need image mode on to fix the upstream icons!

Implemented a workaround in https://gitlab.cee.redhat.com/quarkus-documentation/quarkus/-/merge_requests/1132 to manually add the red hat asciidoc admonition icons as pngs to our repo.
All looks good except for call outs in code snippets on Chrome. I will create another JIRA to fix this. Agreed with Stefan and Sheila the new issue with callouts is less serious than this icon issue.